81333900629 has 2 divisors, whose sum is σ = 81333900630. Its totient is φ = 81333900628.

The previous prime is 81333900619. The next prime is 81333900779. The reversal of 81333900629 is 92600933318.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 75265179025 + 6068721604 = 274345^2 + 77902^2 .

It is a cyclic number.

It is not a de Polignac number, because 81333900629 - 2²⁴ = 81317123413 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 81333900629.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81333900619) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40666950314 + 40666950315.

It is an arithmetic number, because the mean of its divisors is an integer number (40666950315).

Almost surely, 2^81333900629 is an apocalyptic number.

It is an amenable number.

81333900629 is a deficient number, since it is larger than the sum of its proper divisors (1).

81333900629 is an equidigital number, since it uses as much as digits as its factorization.

81333900629 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 209952, while the sum is 44.

The spelling of 81333900629 in words is "eighty-one billion, three hundred thirty-three million, nine hundred thousand, six hundred twenty-nine".